Differences between the multiferroic properties of hexagonal and orthorhombic ion-doped YFeO3nanoparticles

Abstract

The multiferroic properties of ion-doped hexagonal and orthorhombic YFeO3(YFO) nanoparticles (NPs) are studied theoretically. The magnetization [Formula: see text] in h-YFO NPs increases, whereas for o-YFO NPs it decreases with decreasing NP size. In the dielectric constant (DC) both h- and o-YFO have a peak around [Formula: see text] and 460 K, respectively, but only in h-YFO an anomaly appears at [Formula: see text] K in the DC and the polarization which could be connected with a possible [Formula: see text]–[Formula: see text] phase transition. The polarization in pure and Bi-doped o-YFO NPs increases with increasing magnetic field. [Formula: see text] is studied by doping of a o-YFO NP with Ti[Formula: see text] ions at the octahedral Fe[Formula: see text] sites. [Formula: see text] in undoped YFO shows a small kink at [Formula: see text] K, whereas in the doped YFO it shows at [Formula: see text]480 K. By different ion doping on the Y or Fe sites in YFO there is a transformation from the h- to the o-phase or vice versa. In Mn-doped o-YFO a spin-reorientation transition appears. The bandgap of h-YFO is smaller compared to that of o-YFO.